"I still believe it's an advantage if you know how to win a U.S. Open," said Federer, shut out so far this year on the game's biggest stages. "It's a tough tournament to win."

There were questions during media day on Saturday about a "different" Federer and whether Nadal was a clear favorite even though the Spaniard has never been past the quarterfinals here.

That's what happens when you've beaten your rival in two Grand Slam finals this year and won an Olympic gold medal that both players flew halfway around the world to pursue just two weeks before the Open.

American James Blake squashed Federer's Olympic hopes in the quarterfinals in Beijing, beating the Swiss star for the first time after winning just one set in eight previous matches.

"Well, I hope it wasn't too different," Blake said when asked which Federer he beat. "I think he definitely didn't have his best day against me, but playing him nine times — I guess he's bound to have one off day out of all of them, because there are times when I felt like there was nothing I could do."

Nadal dismissed talk of a changing landscape and more pressure accompanying his rise to the top spot.

"The goal is still the same and the pressure is still the same," said Nadal, who opens on Monday against German qualifier Bjorn Phau in Arthur Ashe Stadium. "The goal is to continue to improve my tennis and to continue playing a very good tournament."

"Rafa will now feel what I had to feel for a very long time," Federer said. "So it will be interesting to see how he handles it, but so far he's been great and he's played so well on all surfaces now. Maybe it's nice to go into a Grand Slam for a change not having No. 1 next to me, and it should be interesting."

Andy Roddick, among the players to hand Federer one of his 12 losses this year, thinks Nadal deserves to be called the clear favorite at the U.S. Open simply because he's "playing the best tennis."

But he's not ready to give up on Federer, who is dangerously close to ending a five-year run with at least one Grand Slam singles title.

"I think it's tough to play perfect for five years in a row," Roddick said. "I think one big result and it's turned around for him. I know pretty much every player except for one that would take his bad year. So I think you have to use a little bit of perspective. He's created a monster for himself."

Venus and Serena Williams sidestepped questions about a disappointing draw that would have them meeting in the quarterfinals after they played the final at Wimbledon. That's what happens with random seedings like fourth (Serena) and seventh (Venus).

The sisters said they aren't anywhere near being finished with tennis and want to make the question of the draw moot by rising to the top two spots in the rankings.

"That's the plan, but I don't think either one of us is aiming for two," Venus Williams said.